This application relates to wind turbines, and more particularly to a teeter mechanism for a multiple-bladed wind turbine.
Wind turbines utilizing long turbine blades on the order of 50 meters (164 feet) or more have been used to generate electricity. Due to the length of such turbine blades, wind speed can vary greatly along the span of the turbine blades, in particular as a function of altitude from ground level. For example, a distal end of the turbine blade may experience significantly different wind speeds at lower and upper rotational positions.
This variation in wind speed, known as “wind shear,” can cause the turbine blades to experience unequal loads on each blade. On wind turbines utilizing two blades, an offset pin on the rotor hub has been used to permit the blades to teeter such that an axis of rotation of the blades changes and the wind turbine experiences a more even load. However, this configuration is not effective for wind turbines having more than two blades.